On the individual ergodic theorem for subsequences
On the integral operators of the third kind.
On the intertwinings of regular dilations
The aim of this paper is to find conditions that assure the existence of the commutant lifting theorem for commuting pairs of contractions (briefly, bicontractions) having (*-)regular dilations. It is known that in such generality, a commutant lifting theorem fails to be true. A positive answer is given for contractive intertwinings which doubly intertwine one of the components. We also show that it is possible to drop the doubly intertwining property for one of the components in some special cases,...
On the invariant subspace problem in Banach spaces
On the inversion of pseudo-differential operators
On the invertibility of isometric semigroup representations
Let T be a representation of a suitable abelian semigroup S by isometries on a Banach space. We study the spectral conditions which will imply that T(s) is invertible for each s in S. On the way we analyse the relationship between the spectrum of T, Sp(T,S), and its unitary spectrum . For or , we establish connections with polynomial convexity.
On the ishikawa iteration process in Hilbert spaces.
On the isomorphism of cartesian products of locally convex spaces
On the iterated Green functions on a bounded domain and their related Kato class of potentials.
On the iterative construction of a solution of nonlinear elliptic boundary value problems
On the iterative process of solving nonlinear operator equations in PTL-spaces
On the iterative test for j-contractive mappings in uniform spaces
Edelstein iterative test for j-contractive mappings in uniform spaces is established.
On the joint numerical status and tensor products.
On the joint spectral radii of commuting Banach algebra elements
Some inequalities are proved between the geometric joint spectral radius (cf. [3]) and the joint spectral radius as defined in [7] of finite commuting families of Banach algebra elements.
On the joint spectral radius of a nilpotent Lie algebra of matrices
For a complex nilpotent finite-dimensional Lie algebra of matrices, and a Jordan-Hölder basis of it, we prove a spectral radius formula which extends a well-known result for commuting matrices.
On the joint spectral radius of commuting matrices
For a commuting n-tuple of matrices we introduce the notion of a joint spectral radius with respect to the p-norm and prove a spectral radius formula.
On the Jordan model operators
On the Kantorovich-Rubinstein maximum principle for the Fortet-Mourier norm
A new version of the maximum principle is presented. The classical Kantorovich-Rubinstein principle gives necessary conditions for the maxima of a linear functional acting on the space of Lipschitzian functions. The maximum value of this functional defines the Hutchinson metric on the space of probability measures. We show an analogous result for the Fortet-Mourier metric. This principle is then applied in the stability theory of Markov-Feller semigroups.
On the Kleinecke-Shirokov Theorem for families of derivations
It is proved that Riesz elements in the intersection of the kernel and the closure of the image of a family of derivations on a Banach algebra are quasinilpotent. Some related results are obtained.
On the Krall-type polynomials.